Current methods for temporarily connecting to or capping expanded tubing or other similar male shapes made of a material which is not readily deformable; e.g., expanded copper tubing, rigid plastics, hardened steel, etc, are often accomplished with complex, large, or unreliable couplings. Various methods and structures have been used to attach couplings to such tubing. For example, ball and sleeve attachment mechanisms have been used with couplings. In such mechanisms, however, the separation force between the coupling and the tubing is concentrated at the balls which results in a point loading (also referred to as undistributed loading) between the balls and the tubing or other insert. This makes for a relatively weak attachment to the tubing and/or potential deformation of the tubing when the coupling is subjected to high pressure.
In U.S. Pat. No. 4,647,081 to Landgraf et al. there is disclosed a latching mechanism using a resilient ring; however, the latching mechanism is of the point loading nature. The latching mechanism uses a plurality of balls on a female fitting. The balls are covered by a continuous resilient ring which retains the balls in place. The male fitting includes a cooperating groove. When the female fitting is coupled to the male fitting, the resilient spring forces the balls into the groove on the male fitting to latch it in place. The balls make contact with the male fitting at spaced apart locations resulting in a point loading.
Provision of a fluid-tight seal between the couplings and their corresponding tubing is often achieved utilizing a manually applied mechanical loading which is often short-lived and unreliable. Often O-rings are used as the sealing means for coupling mechanisms. Sealing with O-rings is typically accomplished by squeezing an elastomeric ring between the two juxtaposed surfaces where fluid sealing is required. When the seal is formed between the tubing and an interior wall of a coupling bore, it is often required that the tubing have a tapered and smooth surface on the end so as to prevent damage to the O-ring positioned in a wall of the bore upon insertion of the tubing into the bore of the coupling. Often it is not feasible to provide the tubing with such an end. Furthermore, the coupling may be used in existing applications where the tubing end has not been tapered or smoothed.
In those situations where the fluid lines are pressured to a substantial degree, it is often necessary to release the internal air (gas) pressure of the coupled fluid line before disconnecting to prevent rapid separation and the subsequent hazard to personnel. This is normally accomplished by use of external means which is cumbersome and time consuming.
The present invention overcomes the above-enumerated problems and other shortcomings associated with current couplings.